Film forming apparatus source supply apparatus, and film forming method

ABSTRACT

A film forming apparatus for forming a film on a substrate by transferring a source gas generated from a low-vapor-pressure source to a process container by a carrier gas includes: a source container configured to receive and heat the low-vapor-pressure source; a first gas pipe configured to supply the carrier gas to the source container; a second gas pipe connecting the source container and the process container; a first opening and closing valve provided in the second gas pipe; and a measurement part configured to measure a flow rate of the source gas flowing through the second gas pipe, wherein the second gas pipe is disposed on a central axis of the process container, and wherein the source container is offset with respect to the central axis of the process container.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2018-137083, filed on Jul. 20, 2018, theentire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a film forming apparatus, a sourcesupply apparatus, and a film forming method.

BACKGROUND

There is an existing technique of carrying a source gas generated byvaporizing a low-vapor-pressure source to a process container using acarrier gas so as to form a film on a substrate (see, for example,Patent Document 1).

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese laid-open publication No. 2009-84625

SUMMARY

An aspect of the present disclosure provides a film forming apparatusfor forming a film on a substrate by transferring a source gas generatedfrom a low-vapor-pressure source to a process container by a carriergas. The film forming apparatus includes: a source container configuredto receive and heat the low-vapor-pressure source; a first gas pipeconfigured to supply the carrier gas to the source container; a secondgas pipe connecting the source container and the process container; afirst opening and closing valve provided in the second gas pipe; and ameasurement part configured to measure a flow rate of the source gasflowing through the second gas pipe, wherein the second gas pipe isdisposed on a central axis of the process container, and wherein thesource container is offset with respect to the central axis of theprocess container.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentdisclosure, and together with the general description given above andthe detailed description of the embodiments given below, serve toexplain the principles of the present disclosure.

FIG. 1 is a schematic view illustrating a configuration of a filmforming apparatus according to a first embodiment.

FIG. 2 is a schematic view illustrating a configuration of a filmforming apparatus according to a second embodiment.

FIG. 3 is a schematic view illustrating a configuration of a filmforming apparatus according to a third embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. In the followingdetailed description, numerous specific details are set forth in orderto provide a thorough understanding of the present disclosure. However,it will be apparent to one of ordinary skill in the art that the presentdisclosure may be practiced without these specific details. In otherinstances, well-known methods, procedures, systems, and components havenot been described in detail so as not to unnecessarily obscure aspectsof the various embodiments.

Hereinafter, non-restrictive embodiments of the present disclosure willbe described with reference to the accompanying drawings. In all of theaccompanying drawings, the same or corresponding members or componentswill be denoted by the same or corresponding reference numerals, andredundant descriptions will be omitted.

First Embodiment

As to a film forming apparatus according to a first embodiment, anapparatus for forming a ruthenium (Ru) film through a chemical vapordeposition (CVD) method will be described by way of example. FIG. 1 is aschematic view illustrating a configuration example of the film formingapparatus according to the first embodiment.

As illustrated in FIG. 1, a film forming apparatus 1 has a substantiallycylindrical airtight process container 10. A susceptor 12 is provided inthe process container 10. The susceptor 12 supports a semiconductorwafer (hereinafter referred to as “wafer W”), which is an example of asubstrate, in a horizontal position. The susceptor 12 is supported by asubstantially cylindrical support member 14 provided at the center of abottom wall of the process container 10. A heater 16 is embedded in thesusceptor 12. A heater power supply 18 is connected to the heater 16,and a heater controller (not illustrated) controls the heater powersupply 18 based on a detection signal of a thermocouple (notillustrated) provided in the susceptor 12. Thus, the wafer W iscontrolled to a desired temperature via the susceptor 12. The susceptor12 is provided with three lift pins (not illustrated) configured toprotrude and retract with respect to the surface of the susceptor 12 soas to move the wafer W supported by the lift pins upward and downward.

A gas discharge mechanism 20 configured to uniformly introduce a processgas, which is for forming a Ru film, to the wafer W on the susceptor 12in the process container 10 is provided on a ceiling wall of the processcontainer 10 so as to face the susceptor 12. The gas discharge mechanism20 discharges a gas supplied from a gas supply mechanism 40 (describedlater) to the interior of the process container 10. A gas introductionport 22, through which the gas is introduced, is formed above the gasdischarge mechanism 20.

An exhaust chamber 28 protrudes downward from the bottom wall of theprocess container 10. An exhaust pipe 30 is connected to the lateralsurface of the exhaust chamber 28. An exhaust device 32 having a vacuumpump and a pressure control valve is connected to the exhaust pipe 30.The exhaust device 32 evacuates the interior of the process container 10so as to reduce the pressure in the process container 10 to a desiredpressure.

A loading and unloading port 34, through which the wafer W is loaded andunloaded between the process container 10 and a transfer chamber (notillustrated) depressurized to a desired pressure, is provided in a sidewall of the process container 10. The loading and unloading port 34 isopened or closed by a gate valve 36.

The gas supply mechanism 40 has a source container 42 receivingruthenium carbonyl (Ru₃(CO)₁₂), which is an example of alow-vapor-pressure source. The source container 42 is arranged to beoffset from the central axis C of the process container 10. Thus, athird straight pipe portion 485 of a source gas supply pipe 48(described later) can be arranged on the central axis C of the processcontainer 10. In addition, the source container 42 is disposed at aposition higher than the process container 10, for example, above theceiling wall of the process container 10. The width of the sourcecontainer 42 is, for example, narrower than the width of the processcontainer 10. A heater 44 is provided around the source container 42. Byheating and sublimating Ru₃(CO)₁₂ in the source container 42 using theheater 44, Ru₃(CO)₁₂ gas is generated in the source container 42. Acarrier gas supply pipe 46 and the source gas supply pipe 48 areinserted into the source container 42.

The carrier gas supply pipe 46 has one end inserted into the sourcecontainer 42 and the other end connected to a carrier gas supply source(not illustrated). The carrier gas supply pipe 46 supplies CO gas, whichis an example of the carrier gas supplied from the carrier gas supplysource, to the source container 42 from above. The carrier gas supplypipe 46 is, for example, a pipe having a nominal diameter of ⅛ to ½inches. An opening/closing valve V1 is provided in the carrier gassupply pipe 46.

The source gas supply pipe 48 has one end inserted into the sourcecontainer 42 and the other end connected to the gas introduction port 22of the gas discharge mechanism 20. The source gas supply pipe 48 is alarge-diameter pipe having an outer diameter larger than that of thecarrier gas supply pipe 46, and is, for example, a pipe having a nominaldiameter of 40A to 80A. The source gas supply pipe 48 includes aplurality of straight pipe portions and a plurality of bent portionsconnecting the straight pipe portions. More specifically, the source gassupply pipe 48 includes a first straight pipe portion 481, a first bentportion 482, a second straight pipe portion 483, a second bent portion484, and the third straight pipe portion 485 disposed in order from theside of the source container 42.

The first straight pipe portion 481 extends vertically upward from thesource container 42, and the upper end of the first straight pipeportion 481 communicates with the first bent portion 482. The first bentportion 482 is bent in an L shape in the horizontal direction from theupper end of the first straight pipe portion 481, and communicates withthe second straight pipe portion 483. The second straight pipe portion483 extends in the horizontal direction from the first bent portion 482,and communicates with the second bent portion 484. The second bentportion 484 is bent in an L shape vertically downward from the secondstraight pipe portion 483, and communicates with the third straight pipeportion 485. The third straight pipe portion 485 extends verticallydownward from the second bent portion 484, and communicates with the gasintroduction port 22. With this configuration, even if particles aregenerated in the source container 42, the particles are trapped by thefirst straight pipe portion 481, which forms a flow path directedvertically upward. Thus, it is possible to suppress the particles fromentering the process container 10.

In addition, since the third straight pipe portion 485 is disposed onthe central axis C of the process container 10, disturbance of a gasflow that may occur in the first bent portion 482 and the second bentportion 484 is reduced by the third straight pipe portion 485, making itpossible to supply a uniform flow of Ru₃(CO)₁₂ gas to the gasintroduction port 22. Therefore, it is possible to stably supply theRu₃(CO)₁₂ gas at a high flow rate.

The length of the third straight pipe portion 485 may in someembodiments be longer than the lengths of the first straight pipeportion 481 and the second straight pipe portion 483. In thisconfiguration, it is possible to reduce disturbance of the gas flow thatmay occur, particularly, in the first bent portion 482 and the secondbent portion 484. The pipe length of the source gas supply pipe 48 maybe 0.3 m to 1.0 m.

An opening and closing valve V2, an opening and closing valve V3, and ameasurement part 50 are provided in the source gas supply pipe 48 inthis order from the side of the source container 42. The measurementpart 50 measures the flow rate of the Ru₃(CO)₁₂ gas flowing through thesource gas supply pipe 48. The measurement part 50 may include acapacitance manometer 501 and a Fourier transform infrared spectrometer(FTIR) 502. The capacitance manometer 501 detects a pressure (totalpressure) in the source gas supply pipe 48. The FTIR 502 measures apartial pressure of the Ru₃(CO)₁₂ gas flowing in the source gas supplypipe 48. Based on the flow rate of the CO gas, the total pressure in thesource gas supply pipe 48, and the partial pressure of the Ru₃(CO)₁₂ gasflowing in the source gas supply pipe 48, the flow rate of the Ru₃(CO)₁₂flowing in the source gas supply pipe 48 is calculated. As describedabove, since the flow rate of the Ru₃(CO)₁₂ gas flowing in the sourcegas supply pipe 48 is measured using the FTIR 502, conductance of thesource gas supply pipe 48 is not decreased. Therefore, it is possible tosupply the Ru₃(CO)₁₂ gas generated from Ru₃(CO)₁₂, which is alow-vapor-pressure source, into the process container 10 at a high flowrate. When the flow rate of the Ru₃(CO)₁₂ gas flowing in the source gassupply pipe 48 is measured using a mass flow controller, conductance ofthe source gas supply pipe 48 is decreased. Therefore, it is difficultto supply the Ru₃(CO)₁₂ gas generated from Ru₃(CO)₁₂, which is alow-vapor-pressure source, into the process container 10 at a high flowrate.

A bypass pipe 52 is provided so as to connect a location in the carriergas supply pipe 46 between the opening and closing valve V1 and thecarrier gas supply source and a location in the source gas supply pipe48 between the opening and closing valve V2 and the opening and closingV3. An opening and closing valve V4 is provided in the bypass pipe 52.By closing the opening and closing valves V1 and V2 and opening theopening and closing valves V4 and V3, the CO gas supplied from thecarrier gas supply source is supplied to the source gas supply pipe 48via the carrier gas supply pipe 46 and the bypass pipe 52 withoutpassing through the source container 42. Thus, the source gas supplypipe 48 can be purged.

An Evac pipe 54 is branched out from the middle of the source gas supplypipe 48 to evacuate the source gas supply pipe 48. The Evac pipe 54 hasone end connected to a location in the source gas supply pipe 48 betweenthe opening and closing valve V2 and the opening and closing valve V3and the other end connected to the exhaust pipe 30. An opening andclosing valve V5 is provided in the Evac pipe 54. By closing the openingand closing valves V3 and V4 and opening the opening and closing valvesV1, V2, and V5, CO gas is introduced into the source container 42 fromthe carrier gas supply source through the carrier gas supply pipe 46.Then, the Ru₃(CO)₁₂ gas sublimated in the source container 42 istransferred by the CO gas, and is exhausted through the source gassupply pipe 48 and the Evac pipe 54. With this configuration, it ispossible to supply Ru₃(CO)₁₂ gas to the process container 10 after theflow rate of Ru₃(CO)₁₂ gas is stabilized in a state where Ru₃(CO)₁₂ gasis supplied to the Evac pipe 54 without being supplied to the processcontainer 10.

In the gas supply mechanism 40, by closing the opening and closingvalves V4 and V5 and opening the opening and closing valves V1, V2, andV3, CO gas is introduced into the source container 42 from the carriergas supply source through the carrier gas supply pipe 46. Then, theRu₃(CO)₁₂ gas sublimated in the source container 42 is transferred bythe CO gas, and is supplied to the process container 10 through thesource gas supply pipe 48 and the gas discharge mechanism 20. Inaddition, by closing the opening and closing valves V3 and V4 andopening the opening and closing valves V1, V2, and V5, CO gas isintroduced into the source container 42 from the carrier gas supplysource through the carrier gas supply pipe 46. Then, the Ru₃(CO)₁₂ gassublimated in the source container 42 is transferred by the CO gas, andis exhausted through the source gas supply pipe 48 and the Evac pipe 54by the exhaust device 32.

The film forming apparatus 1 includes a controller 60 that controls theoverall operation of the film forming apparatus 1. The controller 60includes a central processing unit (CPU), a read only memory (ROM), anda random-access memory (RAM). The CPU executes a desired film formingprocess according to a recipe stored in a storage area of the RAM or thelike. In the recipe, control information on devices is set inassociation with process conditions. The control information mayinclude, for example, a gas flow rate, a pressure, a temperature, and aprocess time. A program used by the recipe and the controller 60 may bestored in, for example, a hard disk or semiconductor memory. Inaddition, the recipe may be set in a predetermined position and read outin the state where the recipe is stored in a storage medium readable bya portable computer, such as a CD-ROM or a DVD. In addition, thecontroller 60 may be provided separately from the film forming apparatus1.

In addition, the controller 60 controls the degree to which the openingand closing valve V3 opens based on the flow rate of the Ru₃(CO)₁₂ gasmeasured by the measurement part 50. For example, the controller 60controls the degree to which the opening and closing valve V3 opens suchthat the flow rate of the Ru₃(CO)₁₂ gas measured by the measurement part50 is kept constant. Specifically, when the flow rate of theRu_(z)(CO)₁₂ gas measured by the measurement part 50 is smaller than apredetermined set flow rate, the controller 60 controls the degree towhich the opening and closing valve V3 opens to be increased. As thisdecreases the pressure in the source container 42, the amount of theRu₃(CO)₁₂ gas generated by sublimation of Ru₃(CO)₁₂ in the sourcecontainer 42 is increased. As a result, the flow rate of the Ru₃(CO)₁₂gas supplied to the process container 10 is increased, and approachesthe predetermined set flow rate. Meanwhile, when the flow rate of theRu₃(CO)₁₂ gas measured by the measurement part 50 is greater than apredetermined set flow rate, the controller 60 controls the openingdegree of the opening and closing valve V3 to be reduced. Since such acontrol increases the pressure in the source container 42, the amount ofRu₃(CO)₁₂ gas generated by sublimation of Ru₃(CO)₁₂ in the sourcecontainer 42 is decreased. As a result, the flow rate of Ru₃(CO)₁₂ gassupplied to the process container 10 is decreased, and approaches thepredetermined set flow rate.

In addition, the controller 60 calculates a remaining amount ofRu₃(CO)₁₂ in the source container 42 based on the flow rate of theRu₃(CO)₁₂ gas measured by the measurement part 50. For example, thecontroller 60 calculates a used amount of Ru₃(CO)₁₂ based on the flowrate of the Ru₃(CO)₁₂ gas measured by the measurement part 50 and asupply time of the Ru₃(CO)₁₂ gas. Then, the controller 60 calculates theremaining amount of Ru₃(CO)₁₂ by subtracting the used amount ofRu₃(CO)₁₂ from an amount of Ru₃(CO)₁₂ immediately after replacing thesource container 42. The controller 60 may display the calculatedremaining amount of Ru₃(CO)₁₂ on a display (not illustrated) of the filmforming apparatus 1. In addition, the controller 60 may predict areplacement cycle of the source container 42 based on the calculatedremaining amount of Ru₃(CO)₁₂, and may display the prediction result onthe display.

Next, a method of forming a Ru film in the film forming apparatus 1 ofthe first embodiment will be described. The following film formingmethod is executed by controlling each part of the film formingapparatus 1 using the controller 60. In the following description, it isassumed that all of the opening and closing valves V1 to V5 are closedin an initial state.

First, the gate valve 36 is opened, and a wafer W is loaded into theprocess container 10 from the loading and unloading port 34 and isplaced on the susceptor 12. The wafer W is heated on the susceptor 12which has been heated by the heater 16 to a desired temperature (e.g.,100 degrees C. to 300 degrees C.). Subsequently, the interior of theprocess container 10 is evacuated by the vacuum pump of the exhaustdevice 32, and is depressurized to a predetermined pressure (e.g., 1 Pato 100 Pa).

Subsequently, by opening the opening and closing valves V1 and V2, COgas as a carrier gas is blown into the source container 42 through thecarrier gas supply pipe 46. In addition, by heating the source container42 using the heater 44, Ru₃(CO)₁₂ is sublimated in the source container42 and Ru₃(CO)₁₂ gas is generated. In addition, by opening the openingand closing valve V3, Ru₃(CO)₁₂ gas is transferred by the CO gas, and isintroduced into the process container 10 through the source gas supplypipe 48 and the gas discharge mechanism 20. Therefore, ruthenium (Ru)generated by thermal decomposition of Ru₃(CO)₁₂ gas is deposited on thesurface of the wafer W. and an Ru film having a predetermined filmthickness is formed on the surface of the wafer W.

At this time, the measurement part 50 measures the flow rate ofRu₃(CO)₁₂ gas flowing in the source gas supply pipe 48. Then, thecontroller 60 controls the degree to which the opening and closing valveV₃ opens based on the flow rate of the Ru₃(CO)₁₂ gas measured by themeasurement part 50 such that the flow rate of Ru₃(CO)₁₂ gas introducedinto the process container 10 is kept constant. In this way, the flowrate of Ru₃(CO)₁₂ gas introduced into the process container 10 iscontrolled base on the flow rate of the Ru₃(CO)₁₂ gas measured by themeasurement part 50 (the capacitance manometer 501 and the FTIR 502)provided in the vicinity of the process container 10. Therefore, it ispossible to control the flow rate of the Ru₃(CO)₁₂ gas introduced intothe process container 10 with high accuracy.

In some embodiments, before introducing the Ru₃(CO)₁₂ gas into theprocess container 10, by opening the opening and closing valves V1, V2,and V5 in a state where the opening and closing valves V3 and V4 areclosed, Ru₃(CO)₁₂ gas may be exhausted through the Evac pipe 54 togetherwith the CO gas for a predetermined time. This makes it possible tosupply the Ru₃(CO)₁₂ gas into the process container 10 after the flowrate of Ru₃(CO)₁₂ gas sublimated in the source container 42 isstabilized without being supplied to the process container 10.

As described above, according to the first embodiment, the source gassupply pipe 48 is disposed on the central axis C of the processcontainer 10, and the source container 42 is arranged to be offset withrespect to the central axis C of the process container 10. Thus, it ispossible to reduce disturbance of the gas flow in the source gas supplypipe 48 and to supply a uniform flow of Ru₃(CO)₁₂ to the gasintroduction port 22. As a result, it is possible to stably supplyRu₃(CO)₁₂ gas at a high flow rate.

Second Embodiment

A film forming apparatus according to a second embodiment will bedescribed. FIG. 2 is a schematic view illustrating a configuration ofthe film forming apparatus according to the second embodiment.

As illustrated in FIG. 2, in a film forming apparatus IA of the secondembodiment, a second measurement part 70 including a capacitancemanometer 701 and a FTIR 702 is provided at the downstream side of theopening and closing valve V5 in the Evac pipe 54. The capacitancemanometer 701 and the FTIR 702 may have the same configuration as thecapacitance manometer 501 and the FTIR 502 provided in the source gassupply pipe 48. Since the other components are the same as those of thefirst embodiment, differences will be mainly described in this section.

In the second embodiment, the flow rate of the Ru₃(CO)₁₂ gas flowingthrough the Evac pipe 54 is measured by the second measurement part 70in a state where the Ru₃(CO)₁₂ gas and CO gas flow in the Evac pipe 54by closing the opening and closing valve V3 and opening the opening andclosing valve V5. Then, the controller 60 controls the degree to whichthe opening and closing valve V5 opens such that the flow rate of theRu₃(CO)₁₂ gas measured by the second measurement part 70 is keptconstant. In addition, the controller 60 controls the degree to whichthe opening and closing valve V3 opens based on the degree to which theopening and closing valve V5 opens when the flow rate of the Ru₃(CO)₁₂gas flowing through the Evac pipe 54 becomes constant. Subsequently,Ru₃(CO)₁₂ gas is introduced into the process container 10 by closing theopening and closing valve V5 and opening the opening and closing valveV3. This shortens a time required for the flow rate of the Ru₃(CO)₁₂ gasflowing through the source gas supply pipe 48 to reach a predeterminedset flow rate. As a result, it is possible to shorten a time until theflow rate of Ru₃(CO)₁₂ gas is stabilized after Ru₃(CO)₁₂ gas is suppliedto the process container 10.

Third Embodiment

A film forming apparatus according to a third embodiment will bedescribed. FIG. 3 is a schematic view illustrating a configuration ofthe film forming apparatus according to the third embodiment.

As illustrated in FIG. 3, in ae film forming apparatus 1B of the thirdembodiment, the measurement part 50 is provided at a position closer tothe source container 42 than the branch point of the Evac pipe 54. Sincethe other components are the same as those of the first embodiment,differences will be mainly described in this section.

In the third embodiment, the opening and closing valve V2, themeasurement part 50, and the opening and closing valve V3 are providedin the source gas supply pipe 48 in this order from the side of thesource container 42, and the measurement part 50 is provided at alocation closer to the source container 42 than the branch point of theEvac pipe 54.

In the third embodiment, the flow rate of Ru₃(CO)₁₂ gas flowing throughthe Evac pipe 54 is measured by the measurement part 50 in a state whereRu₃(CO)₁₂ gas and CO gas flow in the Evac pipe 54 by closing the openingand closing valve V3 and opening the opening and closing valve V5. Then,the controller 60 controls the opening degree of the opening and closingvalve V5 such that the flow rate of Ru₃(CO)₂ gas measured by themeasurement part 50 is kept constant. In addition, the controller 60controls the degree to which the opening and closing valve V3 opensbased on the degree to which the opening and closing valve V5 opens whenthe flow rate of the Ru₃(CO)₁₂ gas flowing through the Evac pipe 54becomes constant. Subsequently, Ru₃(CO)₁₂ gas is introduced into theprocess container 10 by closing the opening and closing valve V5 andopening the opening and closing valve V3. This shortens a time requiredfor the flow rate of the Ru₃(CO)₁₂ gas flowing through the source gassupply pipe 48 to reach a predetermined set flow rate. As a result, itis possible to shorten a time until the flow rate of the Ru₃(CO)₁₂ gasis stabilized after Ru₃(CO)₁₂ gas is supplied to the process container10.

In the third embodiment, it is possible to measure the flow rate of theRu₃(CO)₁₂ gas flowing through the Evac pipe 54 and the flow rate of theRu₃(CO)₁₂ gas flowing through the source gas supply pipe 48 by thesingle measurement part 50.

In the above embodiments, the carrier gas supply pipe 46 is an exampleof a first gas pipe, the source gas supply pipe 48 is an example of asecond gas pipe, the gas supply mechanism 40 is an example of a sourcesupply, and the opening and closing valve V5 is an example of a secondopening and closing valve.

Although the above-mentioned embodiments have been described with a casewhere the low-vapor-pressure source is Ru₃(CO)₁₂, the present disclosureis not limited thereto, and another source may be used as thelow-vapor-pressure source as long as the source has a vapor pressurethat ranges from 0.1 Pa to 100 Pa at 80 degrees C. Tungsten hexachloride(WC₁₆) may be an example of such a source.

According to the present disclosure, it is possible to stably supply asource gas generated from a low-vapor-pressure source at a high flowrate.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the embodiments described herein maybe embodied in a variety of other forms. Furthermore, various omissions,substitutions and changes in the form of the embodiments describedherein may be made without departing from the spirit of the disclosures.The accompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thedisclosures.

What is claimed is:
 1. A film forming apparatus for forming a film on asubstrate by transferring a source gas generated from alow-vapor-pressure source to a process container by a carrier gas, theapparatus comprising: a source container configured to receive and heatthe low-vapor-pressure source; a first gas pipe configured to supply thecarrier gas to the source container; a second gas pipe connecting thesource container and the process container; a first opening and closingvalve provided in the second gas pipe; and a measurement part configuredto measure a flow rate of the source gas flowing through the second gaspipe, wherein the second gas pipe is disposed on a central axis of theprocess container, and wherein the source container is offset withrespect to the central axis of the process container.
 2. The filmforming apparatus of claim 1, wherein the second gas pipe comprises aplurality of straight pipe portions and a plurality of bent portionsconnecting the straight pipe portions, and wherein one straight pipeportion among the plurality of straight pipe portions, which has one endconnected to the process container, has a pipe length greater than otherstraight pipe portions.
 3. The film forming apparatus of claim 1,wherein the source container is disposed at a position higher than theprocessing contain.
 4. The film forming apparatus of claim 1, whereinthe source container has a width narrower than a width of the processcontainer.
 5. The film forming apparatus of claim 1, further comprising:a controller configured to control a degree to which the first openingand closing valve opens, wherein the controller controls the degree towhich the first opening and closing valve opens based on the flow rateof the source gas measured by the measurement part.
 6. The film formingapparatus of claim 5, wherein the controller performs a control toincrease the degree to which the first opening and closing valve openswhen the flow rate of the source gas measured by the measurement part isless than a predetermined set flow rate.
 7. The film forming apparatusof claim 5, wherein the controller performs a control to decrease thedegree to which the first opening and closing valve opens when the flowrate of the source gas measured by the measurement part is greater thana predetermined set flow rate.
 8. The film forming apparatus of claim 5,further comprising: an Evac pipe branched from a middle of the secondgas pipe and configured to evacuate the second gas pipe, wherein thefirst opening and closing valve and the measurement part are provided atlocations closer to the process container than a branch point of theEvac pipe.
 9. The film forming apparatus of claim 8, further comprising:a second opening and closing valve provided in the Evac pipe; and asecond measurement part configured to measure a flow rate of the sourcegas flowing through the Evac pipe.
 10. The film forming apparatus ofclaim 9, wherein the controller controls a degree to which the secondopening and closing valve opens based on the flow rate of the source gasmeasured by the second measurement part.
 11. The film forming apparatusof claim 10, wherein the controller controls the degree to which thefirst opening and closing valve opens based on the degree to which thesecond opening and closing valve opens.
 12. The film forming apparatusof claim 5, further comprising: an Evac pipe branched from a middle ofthe second gas pipe and configured to evacuate the second gas pipe,wherein the first opening and closing valve and the measurement part areprovided at locations closer to the source container than a branch pointof the Evac pipe.
 13. The film forming apparatus of claim 5, wherein thecontroller calculates a remaining amount of the low-vapor-pressuresource in the source container based on the flow rate of the source gasmeasured by the measurement part.
 14. The film forming apparatus ofclaim 1, wherein the measurement part comprises a Fourier transforminfrared spectrometer and a capacitance manometer.
 15. The film formingapparatus of claim 1, wherein the low-vapor-pressure source isRu₃(CO)₁₂, and wherein the carrier gas is CO gas.
 16. A source supplyapparatus for transferring a source gas generated from alow-vapor-pressure source to a process container by a carrier gas, theapparatus comprising: a source container configured to receive and heatthe low-vapor-pressure source; a first gas pipe configured to supply thecarrier gas to the source container; a second gas pipe connecting thesource container and the process container; an opening and closing valveprovided in the second gas pipe; and a measurement part configured tomeasure a flow rate of the source gas flowing through the second gaspipe, wherein the second gas pipe is disposed on a central axis of theprocess container, and wherein the source container is offset withrespect to the central axis of the process container.
 17. A film formingmethod of forming a film on a substrate by transferring a source gasgenerated from a low-vapor-pressure source to a process container by acarrier gas, the method comprising: generating the source gas by heatingthe low-vapor-pressure source received in a source container, the sourcecontainer being offset with respect to a central axis of the processcontainer; supplying the carrier gas to the source container through afirst gas pipe; and transferring the source gas and the carrier gas tothe process container through a second gas pipe disposed on the centralaxis of the process container.
 18. The film forming method of claim 17,wherein the supplying the carrier gas maintains a constant flow rate ofthe carrier gas.